Electrical alarm system.



F. CASTLE.

ELECTRICAL ALARM SYSTEM. APPLICATION FILED min: 8, 1910.

' I Patented Oct. 25,1910.

f IM II, b

176121 no.3 I 3 UNITED STATES PATENT orrioa FRANK CASTLE, OF

WARD JOSHUA RIDDIFORD, OF WELLI AUCKLAND, NEW ZEALAND', AssrGNon or 'rwo-rrrrrrs ro ED- ne'ron, NEW ZEALAND, TWO-FIFTHS TO WILLIAM EDWARD BIDWILL, OF FEATHERSTON, NEW ZEALAND, AND ONE-TENTH TO LESLIE LOUIS MQDEBMOTT, OF AUCKLAND, NEW ZEALAND.

ELECTRICAL ALARM srs'rnivr.

Application filed June 8, 1910.

Specification of Letters Patent.

Patented Oct. 25, 1910'.

Serial No. 565,710.

To all whom it may concern;

' a building,

I do hereby "therefrom, through closed line wire circuit.

The invention has been designed in order to improve means -for giving the alarm at the central stat-ion upon the local circuit fault in being actuated and also to provide means whereby a breakor cross wire faultin the line wire may be signaled.

The invention consists in theemployment of two relays at the central station and each arranged in, circuit with the closed circuit. One of these relays is made of greater resistance than the other so that the current of the closed circuit is prevented from flowing through it. Thearmature ofthis relay is arranged to close a local indicator alarm circuit when the relay is' energized, while the armature of the weaker relay is arranged to close a separate local indicator alarm circuit when it is deenergized.

A relay circuit is arranged in the building in which the installation 1s placed, such circuit being adapted to the action of thermostats or other appliances. A local battery circuit is also arranged in such adapted to be closed by the movement of the relay. armature. This circuit is placed in series connection with the closed circuit communication leading to the central station so that u on the local battery circuit being complete a current will be sent'through the lines Wires sufliciently strong to overcome the resistance of the stronger relay and cause its armature to be attracted and close the alarm circuit at the station. Means are also provided for indicating the nature of a the wiring of the line wires.

The invention is illustrated in diagramc. WVhen this be closed or opened by.

building and this circuit is matic form in the accompanying drawings, in which Figure l is a diagram of the whole of the circuits in their normal conditions. Figs. 2 and 3 are details views of the-means for lndicating the nature of a fault in the line wire.

InFig. 1 A represents the central station and B represents the building from which the alarm is to be given.

- \Vithin .the building is arranged the thermostat or like circuit a, which may be either an open or closed circuit, but which int-he drawings is represented as an open circuit.

adapted to be closed by the action of a ther niostat Z). A relay 0 is arranged in this circuit and the armature of this relay when in its normal position, serves to keep closed the line wire circuit cl leading to the central station A; A local battery circuit e is also placed'in the building and arranged in open circuit with the line wire (Z and a terminal f to the armature of the relay armature is acted upon by the closing of the relay thermostat circuit a, it will engage with the terminal f and thereby serve to briug'such local circuit battery into series with the battery 9 of the line wire circuit and thus strengthen the current in this latter circuit. I

Twp relays I2 and j are arranged at the station A in circuit with the line wire circuit (land one of these It is'made'of higher. resistance than the other so that the current. from the battery 9 cannot flow through it; It is therefore normally quiet. The other relay j is kept normally energized by the current from the battery 9. The current from the battery circuit 6, when brought into series with the line wire circuit, of sufiicient strength to overcome the resistance of the relay .71 and such relay will 'conse-. quently be energized in the event of the thermostat circuit a being completed.

An alarm 70, and shutter indicator m, are arranged in circuit with a battery 0,. the armaturc of the relay h, and a terminal n adapted to beengaged by such armature,

placed adjacent when the relay is energized in the manner building B is 4 alarm will be sounded and a shutter indicating such fact.

. marked respectively wire closed as shown in Fig. is however adapted to bring the current.

fire, this alarm indicator circuit will be completed and thus the alarm given. The alarm 1 la and battery are also arranged in circuit with a separate shutter indicator p and the armature of the relay 7' and with a terminal r adapted to be en aged by such armature when-the relay is ecnergized and thereby complete such circuit. Thusshould a break occur in the closed line-wire circuit (Z, an dropped Also should any cross wiring or short circuiting of the wires take "place, the alarm will be sounded.

The shutter indicators m and 7) will he fire and fault so that when an alarm is sounded, the attendant may ascertain the cause thereof.

In order to ascertain whether the fault alarm is cans l by a break or by cross wires,

the means shown in Figs. 2 and 2:) may be,

employed. These means consist of a switch 3 that-is interposed in the line wire d at the central station, and normally keeps such 2. The switch from a battery into circuit with such wire by moving. it to one side, as shown in Fig. 3;

\Vhen a faultalarm is given, the switch is moved over-to the position shown in Fig. 3. This will bring the battery into the wire so that if the alarm caused by a cross 'wire the relay 3' will be retinergized by such battery and the alarm circuit broken. Should a break have occurred, the alarm uill continue to sound.

W'hat I do clain'i as my invention, and de she to secure by Letters Patent is 1. In electric alarm systems, the combination with a closedline wire circuit, of a-batt'ery circuit adapted to be switchedintosuch wire circuit by the operation of a thermostat or other local circuit, two relays of respectively differential resistances arranged inthe line wire circuit, and an alarm indicater circuit adapted to be operated' by the posed in the line movement of the armature of each relay, substantially as herein specified.

2. In electric alarm systems, the combination with a closed line wire circuit, of a relays of respectively differential resistances arranged in such circuit, an alarm indicator circuit adapted to be operated by the movement of each relay armature, and means whereby the diii'erential resistances of the relays may be overbalanced upon the opera tion of a thermostat or other lotal circuit, substantially as herein specified.

3. In electric alarinsystenis, the combination with a closed line wire circuit, of a thern'iost-at or other local relay circuit arranged with its relay armature in the-line circuit, a battery circuit adapted to be brought into the line circuit by the movement of the relay armature, a pair of relays of respectively differential resistances arranged in thctline circuit and an alarm indicator cir'cuitadapted to be operated by the movement of each relay armature, substan tiallyas specified.

4. In electric alarm systems, the combination with a closed line wire circuit, of two relays of respectively differential resistances arranged in such circuit, an alarmindicator adapted to be operated by the movement of each relay armature, means whereby fercntial resistances of the relays may be overbalanced upon the operation of a thermostator other" local circuit, aswitch interwire' circuit and a battery adapted to be switched into such circuit by the operation'ot the switch, substantially as specified. v

Dated this 19th day of April 19-10.

In testimony whereof, I have signed this specification in thepresence of two subscribin g witnesses.

. FRANK CASTLE. Witnesses:

Lnsun McDnaiuo'r'r. M. E. on LAzQGE.

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